Co-pyrolysis and chemical looping co-gasification of rice straw and agricultural plastics for hydrogen and power generation: Experimental study and life cycle assessment

Co-pyrolysis and chemical looping co-gasification (CLCG) processes of rice straw (RS) and polyethylene-based agricultural plastic (PE) were experimentally investigated, and systematically explored as strategies for integrated hydrogen and electricity production by life cycle assessment (LCA). Experiments were conducted at 800 °C with a fixed oxygen carrier-to-feedstock ratio of 1:1 to evaluate the impacts of PE blending ratios on the product distributions, gas compositions, and gasification performances. The use of oxygen carriers significantly enhanced syngas yield by over 10%, and the CH4 and C2 hydrocarbon production increased by boosting the PE ratio, while decreased H2 and CO concentrations. The maximum gasification efficiency of 46.86% and carbon conversion efficiency of 59.09% were achieved at the RS/PE ratio of 75:25. The highest hydrogen production (16.44 kg) and electricity production (3.25 MWh) were severally achieved at Scenario 3 and Scenario 4 via energy analysis. The LCA based on eFootprint and Chinese life cycle database showed that the environmental impacts of hydrogen from Scenario 2 and electricity from Scenario 4 were lower than fossil-based counterparts, the global warming potential values were respectively 3.87 kg CO2-eq/kgH2 and 0.87 kg CO2-eq/MWh. These findings presented the technical feasibility and environmental benefits of biomass-plastic co-process and practical insights for sustainable energy development.